The International Baccalaureate may sound like it involves some sort of foreign exchange and a college graduation ceremony, but the IB is actually a comprehensive, demanding, and increasingly popular diploma program for high school juniors and seniors, with a strong academic focus on the world around them. While the IB was created 40 years ago by a Geneva-based educational organization to provide a standardized, high-level curriculum for the children of itinerant diplomats--and while it can be found in 125 countries today--U.S. schools have become the program's biggest consumers by far. As of last November, they comprised 556 of the almost 1,300 schools worldwide offering the two-year IB diploma, and their numbers are increasing by about 10 percent annually. At the heart of the curriculum is a course in the theory of knowledge, which examines different ways of knowing, the role of knowledge in culture, and the connection of knowledge to responsible action. With all the emphasis on achievement, IB programs at some schools enroll a much wider range of students than other traditional advanced programs. This article describes the IB curriculum, how it helps to open doors for college admittance, and how it provides a cross-cultural alternative to Advanced Placement courses.